In a pocket of time

Every time Caleb hears a saying, it happens to him. Pockets with watches appear on his shirt when his mum mentions pockets of time. He soon finds himself in Brumantia, in Mr Bull's china shop.
In Brumantia you can be thrown in prison for a petty crime like being in someone else's shoes or end up in hospital with your fingers crossed or sides split. And just think what 'you're all over the place' can do to you!
Who or what is behind this secret power in idioms and will it stay with Caleb forever?